WO2016055147A1

WO2016055147A1 - Device for withdrawing and transporting a respiratory-gas flow

Info

Publication number: WO2016055147A1
Application number: PCT/EP2015/001945
Authority: WO
Inventors: Hans-Ullrich Hansmann; Andreas Hengstenberg; Uwe Kühn; Gerd Peter; Michael Riecke
Original assignee: Drägerwerk AG & Co. KGaA
Priority date: 2014-10-08
Filing date: 2015-10-05
Publication date: 2016-04-14
Also published as: US10709862B2; CN106794327A; DE102014014661A1; CN106794327B; DE102014014661B4; US20170326326A1

Abstract

The invention relates to a device (10) for withdrawing a respiratory-gas flow (A) from a ventilation system (B) and for transporting the respiratory-gas flow (A) to a gas analysis system (G). The device (10) is designed hose-shaped having an inside (41) and an outside (42) and has at least two hose segments (11, 11'), at least one drying stage (12, 14, 22) having an inside (43, 43') and an outside (44, 44'), and at least one liquid store (13, 21). The drying stage (12, 14, 22) is at least partially composed of a gas-tight and moisture-permeable material in such a way that moisture can be transported from the inside (43, 43') of the drying stage (12, 14, 22) through the gas-tight and moisture-permeable material to the outside (42) of the hose-shaped device (10). At least one drying stage (12, 14, 22) and/or one liquid store (13, 21) is arranged at least partially between two hose segments (11, 11').

Description

Device for removing and transporting a respiratory gas flow

The invention relates to a device for the removal of a breathing gas stream from a

Ventilation system and for transporting the respiratory gas flow to a gas analysis system, as well as a system with such a device.

To monitor the breathing gas composition of a patient - for example, in artificial respiration - it is customary at the mouthpiece or on the Y-piece of the respiratory device or the

Respiratory system to take a breathing gas sample and analyze this with the help of gas sensors. Typically, respiratory gas components such as C0 ₂ , oxygen or anesthetic gases are continuously monitored. In such continuous monitoring, it is important to protect the sensors used (ie the gas analysis system) from unwanted moisture influences - for example from condensate from the humid air - as well as from biological material, such as bacteria, and other contaminants.

In this context, WO 2011/103585 A2 proposes a water trap which has a filter made of a hydrophilic and microporous material. Through the water trap, a breathing gas flow can be passed. The filter can absorb and store condensate contained in the respiratory gas flow.

WO 2011/103585 A2 also provides an additional hydrophobic filter membrane at the exit of this assembly. This filter membrane is intended to prevent excess liquid from being able to penetrate when the hydrophilic filter is saturated.

WO 2010/030226 AI provides a sample gas line, with which a respiratory gas flow can be passed from the patient to a patient gas monitor. This sample gas line is with a

Drying device provided. This drying device is arranged at the end of the sample gas line, directly in front of the patient gas monitor. The breathing gas flowing through the sample gas line is thus cooled to room temperature level when it reaches the drying device, and excess moisture has condensed out. The drying device consists of a

moisture permeable and gas tight polyether / polyamide block copolymer housing filled with a hydrophilic material.

Based on this, it is an object of the present invention to provide an improved device for the removal and transport of respiratory gases between a ventilation system and a gas analysis device. With the help of such an improved device should be ensured, inter alia, that no liquids, contaminants or germs get into the gas analyzer.

1

CONFIRMATION COPY As a solution, the invention provides a device according to claim 1, as well as a system with such a device according to claim 15. Embodiments are each subject of the dependent claims.

In a device for taking a respiratory gas stream from a respiratory system and for transporting the respiratory gas flow to a gas analysis system, the invention provides that the device is formed tubular with an inner side and an outer side and at least two

Hose sections as well

• at least one drying step with inside and outside, and

Having at least one liquid reservoir,

wherein the drying step at least partially such from a gas-tight and

moisture-permeable material is that moisture from the inside of the drying step through the gas-tight and moisture-permeable material is transported to the outside of the device,

and wherein at least one drying stage and / or a liquid storage is at least partially disposed between two tube sections.

In particular, such a device can also provide reliable and unambiguous measurement signals if the respiratory gas sample to be examined, which has been removed by the respiratory system, has a

Flow rate of less than 200 ml of respiratory gas per minute. In particular, it is also conceivable that such a tubular device can be used independently of the use of a conventional water trap. The device according to the invention is therefore particularly suitable for use in paediatrics or the care of premature and newborns. Of course, other applications are not excluded.

Another advantage of the device according to the invention is that - regardless of

The presence or absence of another water trap - prevents liquid drops or accumulation of condensate, which may possibly be present in the sample of breathing gas, from being sucked in by the gas analysis system and damaging it.

The device according to the invention can also be made very small, which is also an advantage in the use of the device in the field of pediatrics and neonatology. In addition, the occurrence of large dead space volumes using this device is largely avoidable. This is favorable in particular in the miniaturization of the respiratory gas sensor system and the associated reduction of the sample gas flow. Another advantage is that the device according to the invention works independently of position. In this way, it is conceivable that it can be used in mobile patient gas monitors.

A hose-shaped device is in this context, for example, a hose having a first and a second end. The hose can have multiple sections and / or Subsections (hose sections, tubular section) have. The outer shape of the tube can be both smooth and be provided with protuberances and / or indentations of various shapes. The inner shape of the tube is preferably a channel with a round, elliptical, or angular cross-section. Inner and outer shapes may be the same or different.

Under a hose is typically understood a flexible conduit for the transport of solid, liquid and / or gaseous substances. A tubular article is therefore typically an article which has the form and function of a flexible conduit for the transport of solid, liquid and / or gaseous substances.

In this case, the substance to be transported, for example breathing gas, can flow into the hose or into the device through the first end. The material to be transported can flow out of the hose or out of the device through the second end. The first end of the hose can therefore also be referred to as the suction end, i. as the end through which the respiratory gas flow from the respiratory system flows into the tubular device. The second end may be referred to as the detector end, i. as the end through which the breathing gas stream flows out of the tubular device and is passed to the gas analysis system. In the hose, i. that is, in the tubular device, the fabric may flow from the first end to the second end. A flowing through the tubular device breathing gas is in the sense of

present invention also referred to as respiratory gas flow.

The first end may be directly or indirectly connected to the respiratory system.

For example, the first end may be connected to a hose or an adapter, which serves in each case for supplying or discharging respiratory gas to or from a patient. The second end may be directly or indirectly connected to the gas analysis system.

A respiratory system in the context of the present invention may be any ventilator, such as an anesthesia machine in the OR or an ICU ventilator. A gas analysis system is preferably a measuring or analyzing device which examines the properties of the respiratory gas flow and, for example, can measure the composition of the respiratory gas flow.

A drying step is typically a device that is built in or on the tubular device, and that serves to remove water from the breathing gas flow. It is also advantageous if such a drying stage is designed to remove liquid water, for example water drops, from the respiratory gas stream.

The fact that the drying stages according to the invention are permeable to water and water vapor, but at the same time for the other components of the breathing air, in particular for oxygen, carbon dioxide, but also anesthetic and other ingredients are impermeable, a separation of moisture from the other breath components can be achieved. For use in conjunction with anesthetic gases, such as in the aspirating

Patient gas measurement in anesthesia workplaces is at the same time the lowest possible

Interaction between the material of the drying stages and possibly contained in the respiratory gas anesthetics beneficial. In particular, it is favorable if it can be prevented that the anesthetic agents interact with the material in such a way that they are stored in the drying stage. Preferably, therefore, as the material modified tetrafluoroethylene polymer (PTFE), for example sulphonated PTFE variants such as Nafion ^® (2- [l- [difluoro [(trifluoroethenyl) oxy] methyl] - l, 2,2,2-tetrafluoroethoxy] - l, l, 2,2-tetrafluoroethanesulfonic acid) are used. Alternatively and / or additionally, it is also possible to use material based on polyether imides or polyether block amides or polyurethane.

It is favorable in any case when the moisture can be transported from the inside of the drying stage directly to the outside of the device. This can be achieved, for example, in that the outside of the drying stage corresponds to the outside of the device. The moisture can easily evaporate from there into the environment and in this way be easily eliminated. In a preferred embodiment, the inner side of the drying step also corresponds to the inside of the device.

The drying stage or the drying stages are preferably arranged between the suction end and the detector end. The respiratory gas flow can thus flow out of the tubular device through the suction end into the tubular device, then through the at least one drying step and finally through the detector end.

It is conceivable in this context that a drying stage is at least partially disposed between two tube sections. The breathing gas stream may then pass through the tubular device in the order of suction end, first tube section, drying step, second tube section, detector end. It can be seen that it is favorable if the first tube section upstream of the drying step and the second tube section downstream of the

Drying stage - in each case with respect to the flow direction of the breathing gas flow - is arranged. In the present case, a partial arrangement between two hose sections is understood to mean that not necessarily the entire drying step, but at least part of the drying step is arranged between the hose sections. For example, it is conceivable that the drying step is arranged on the outside of the device and that a part of the drying step projects into the hose between a first and a second hose section, so that the respiratory gas flow flows from the first hose section into the second hose section past this part . must flow through this part. The same applies with respect to the liquid storage or the. Again, an at least partial arrangement between two tube sections is conceivable and advantageous.

A liquid reservoir in the sense of the present invention is for example an element which

Absorb moisture from the respiratory gas stream and release it back into the respiratory gas stream.

For example, the liquid reservoir can absorb droplet-like moisture (liquid, water droplets) from the respiratory gas flow. At the same time, the liquid storage can also be steam return to the breathing gas flow. In this way it can be ensured that the respiratory gas flow is not too dry by drying with the help of the drying step. It is also conceivable that the liquid storage is part of the drying stage, where it absorbs the excess moisture from the breathing gas flow like a wick. In this case, the wick is preferably arranged as described above between two tube sections. It is also conceivable that the device has a plurality of liquid storage.

A liquid reservoir according to the invention may for example consist of a hydrophilic, porous plastic sintered element. The sintered element may have a volume of 0.15 cm ³ or less. Optionally, the liquid storage may consist of a nonwoven, a plasma-treated PE granules or a matrix of microstructured plastic parts. It can be seen that it is advantageous if the liquid storage is selected from a hydrophilic porous plastic sintered element, a nonwoven, a plasma-treated PE granules or a matrix of microstructured plastic particles.

It is conceivable in particular that the liquid storage is arranged between a first and a second tube section, so that the respiratory gas stream, the device in the order a. first hose section

b. liquid storage

c. second hose section passes.

The liquid is not removed in this way not at the end of the flow path from the respiratory gas flow, but already in the middle part or even in the front part. In this way it is possible, for example, to arrange a drying stage downstream of the liquid store. This can serve, for example, to lower the dew point of the respiratory gas flow. The latter is particularly advantageous if the dew point should be increased by the discharge of liquid, such as in vapor form, from the liquid storage.

It is also advantageous if at least one tube section is formed as a drying step. For example, the device may be designed such that the respiratory gas flow passes through the device in the sequence a) first tube section, b) liquid reservoir, c) a hose section designed as a drying step. Alternatively, of course, the sequence a) designed as a drying stage hose section, b) liquid storage, c) hose section conceivable.

It is particularly favorable, however, when the liquid storage is arranged between two formed as a drying stage hose sections. In this way, the respiratory gas flow passing through the device may be first dried by the first drying step. Is the

Breathing gas flow particularly moist or if it still contains drops of water after that, they can be absorbed by the liquid storage. If moisture was returned from the liquid storage in the respiratory gas, then with the help of the second drying stage of the Respiratory gas stream are dried again. The return of moisture, especially in vapor form, offers the advantage that ultimately the life of the device is increased.

It can be seen that it is favorable if the device has a first and at least one second drying stage, wherein the liquid storage is arranged between the first and the second drying stage, that the respiratory gas flow, the device in order

a. first drying stage

b. liquid storage

c. passes through the second drying step.

In any case, it is preferred if the tube sections each have a diameter which is suitable for allowing a respiratory gas flow of 50 ml per minute. At a desired sample gas flow of 50 mL / min, a suitable inner tube diameter is approximately 1 mm for a gas velocity> 1 m / s. The length of the tube sections designed as drying stages then results from the required exchange surface, which comes into contact with the sample gas in order to achieve the desired dehumidification and thus the required dew point reduction.

It is advantageous if at least one liquid reservoir is formed tubular.

For example, it is conceivable that the device in a particularly simple embodiment variant of a first tube section, which is designed as a drying stage, a second

Hose section, which is designed as a liquid storage, and a third hose section, which in turn is designed as a drying stage consists. In the first tube section, the

Be sucking formed, in the third tube section, the detector end, the second

Hose section in each case directly adjoins the first and the third hose section.

Optionally, the drying effect of the drying steps in this and all other conceivable embodiments, whether described herein or not, can be enhanced by providing these on their outsides with an additional desiccant. For this purpose, e.g. Zeolites with pore sizes of about 4 Å or silica gel suitable. In this way, the surface or length of the drying stages can be additionally reduced, so that as a further positive effect, a material saving can be achieved. It can therefore be seen that it is favorable if a drying agent, preferably zeolite, silica gel or the like, is applied to the outside of at least one drying stage.

In a further embodiment variant according to the invention, the device may have a drying element, which consists of a drying stage and a liquid storage. In this case, the liquid storage can absorb the moisture from the respiratory gas flow and direct it to the drying stage. It is conceivable that the Tröcknungsstufe is arranged on the outside of the device while the liquid storage is partially disposed between two tube sections of the device. The liquid reservoir protrudes into the drying stage. One recognizes, with In other words, at least one liquid reservoir is arranged in one of the drying stages, so that it forms part of a drying element. In other words, it is favorable if at least one liquid store is part of a drying stage.

In order to be able to conduct the moisture with the aid of such a drying element effectively from the respiratory gas flow to the drying stage, it is advantageous if at least one liquid storage is wick-shaped. In particular, this is advantageously the liquid reservoir which is arranged in the drying stage of the drying element.

It is also conceivable for a device according to the invention to have a combination of tubular drying stages, tubular liquid stores and / or drying elements in which a liquid store is arranged in a drying stage as described above. Thus, for example, a first tube section, which is designed as a drying step, followed by a second tube section, which is also designed as a drying step, between these tube sections a wick-shaped liquid storage of a drying element is arranged or projects into the respiratory gas flow, while the drying step which forms the drying element together with the wick-shaped liquid storage, is attached to the outside of the device.

Common to all embodiments is that it is advantageous if the gas-tight,

Moisture-permeable material of the drying stage as low as possible interaction with possibly still contained in the respiratory gas anesthetic gas but nevertheless the highest possible permeation rate (water vapor permeability). It has been shown that it is favorable if the at least one drying step comprises a membrane based on polyether-imides,

Has polyether block amides or polyurethanes.

Examples include the polyether block amide PEBAXTM, PEBAMED ™, PLATILONTM (both from ELF Atochem Germany GmbH) or ARNITEL ™ (from DSM). It is also conceivable that the

Drying stages consist of the material "V 842-1" polyurethane-based manufacturer Collano.

It is particularly advantageous if the polyurethane material is a thermoplastic material.

It is conceivable in this context that the material of which the membrane is made, a material based on polyurethane, wherein the membrane material

a. a density of 0.5 to 1.8 g / cm ³ , preferably 0.7 to 1.5 g / cm ³ , more preferably from 1 to 1.3 g / cm ³ , most preferably from 1.2 ± 0 , 1 g / cm ³ ,

b. a melting range between 100 ° C and 200 ° C, preferably between 120 ° C and 180 ° C, more preferably between 140 ° C and 170 ° C, most preferably from 150 ° C to 160 ° C, and / or c. a water vapor permeability of greater than 500 g / m ² per 24 hours, preferably greater

1000 g / m ² per 24 hours, more preferably greater than 1500 g / m ² per 24 hours, most preferably greater than 2000 g / m ² per 24 hours.

For example, the gas-tight, moisture-permeable material may have a density of 1.2 ± 0.1 g / cm ³ , a melting range of 150 ° C. to 160 ° C. and a water vapor permeability of greater than 2000 g / m ² per 24 hours. For example, it may be advantageous if the membrane is applied to a polyethylene carrier, but other thermoplastics are also conceivable as carriers.

It is also conceivable in any case that the device has a hydrophobic bacterial filter, wherein the bacterial filter preferably has a PTFE membrane with a pore size of 0.45 μηι or less and a water intrusion pressure of 100 kPa or higher. Such a bacterial filter can additionally prevent contamination of the gas analyzer by bacteria or other microorganisms. The bacterial filter can serve as an additional liquid barrier. It is also conceivable that the liquid reservoir and the bacterial filter form a single component. This is particularly space-saving, for example.

As a further aspect, the invention provides a system for breathing gas monitoring of a patient comprising the device according to the invention. In this case, the invention has the features and advantages described in detail above. Favorable is the use of such a system for breathing gas monitoring of a premature or newborn patient. The use of a device according to the invention for breathing gas monitoring of a premature or newborn patient is also advantageous according to the invention. The same applies to a use in small, mobile system in which a position-independent function is favorable, such as transport systems.

Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. Show it :

1 is a schematic representation of a first embodiment of the present invention,

2 shows a schematic representation of a second embodiment of the present invention,

Fig. 3 is a schematic representation of a third embodiment of the present invention.

The embodiment variant of a device 10 according to the invention shown in FIG. 1 has two tube sections 11, 11 'and a liquid store 13 arranged between the two tube sections 11, 11'. The liquid store 13 is tubular in the exemplary embodiment according to FIG.

Both the first tube section 11 and the second tube section 11 'are as

Drying stage 12, 14 formed. In other words, the device 10 has a first one Drying stage 12 and a second drying stage 14, wherein the drying stages 12, 14 are formed tubular. The device 10 further has an inner side 41 and a

Outside 42. Also, the drying stages 12, 14 each have an inside 43 and an outside 44. It can be seen that in the example shown in Fig. 1, the inside 43 of the drying stages 12, 14 of the inside 41 of the device 10 corresponds and that the Outside 44 of the drying stages 12, 14 of the outside 42 of the device 10 corresponds.

The drying stages 12, 14 have a gas-tight, moisture-permeable material. Suitable materials for the embodiment described in Figure 1 and all other (described or not described) are described below in the example "test various

Membrane materials "listed.

The device 10 further has a first end 16 and a second end 17. Through the first end 16, a respiratory gas flow A, which comes from a ventilation system B, into the device 10th

hineinströmen. Through the second end 17, the breathing gas flow A can flow out of the device 10 and out to a gas analysis system G. It can be seen that the respiratory gas flow A, while flowing through the device 10, first flows through the first drying stage 12. Here is in the

Breathing gas flow A contained moisture from the inside 43 of the drying stage 12 and thus from the inside 41 of the device 10 to the outside 44 of the drying stage 12, i. So transported to the outside 42 of the device 10. If larger in the respiratory gas flow A.

Liquid droplets are contained, these can be subsequently taken up by the liquid storage 13. At the same time, the liquid reservoir 13 can also deliver moisture in the form of water vapor to the respiratory gas flow A. In order to prevent the respiratory gas flow A being re-moisturized too much, when passing through the second drying stage 14, again

Moisture from the inside 43 of the drying step 14 and thus from the inside 41 of the device 10 to the outside 44 of the drying step 14, i. So be transported to the outside 42 of the device 10.

The device 10 has a diameter D. This diameter D corresponds to the inner diameter of the tube sections 11, 11 '. In this respect, the drying stages 12, 14 have the same diameter D as the entire apparatus 10. The diameter D is dimensioned such that the respiratory gas flow A has a minute volume of 50 ml / min at a gas velocity of more than 1 m / s. In a preferred embodiment, the diameter D is about 1 mm.

At the second end 17 of the device 10, a bacterial filter 15 is arranged as additional protection. The bacterial filter 15 is hydrophobic and consists of a PTFE membrane with a pore size of 0.45 μηη or less and a water intrusion pressure of 100 kPa or higher.

Overall, FIG. 1 shows a device 10 for removing a respiratory gas flow A from a respiratory system B and for transporting the respiratory gas flow A to a gas analysis system G, wherein the device 10 is tubular with an inner side 41 and an outer side 42 and two tube sections 11, 11 'and two drying stages 12, 14 each having an inner side 43 and an outer side 44, and a liquid storage 13, wherein the drying stage 12, 14 at least partially consists of a gas-tight and moisture-permeable material that moisture from the inside 43 of the drying stage 12, 14 through the gas-tight and moisture-permeable material through to the outside 42 of the tubular device 10 is transportable, and wherein the liquid reservoir 13 is arranged between two tube sections 11 ,

The breathing gas flow A in this embodiment typically has a temperature of about 37 ° C when it enters the first tube section 11 through the end 16. While passing through the

Hose section 11 flows, it cools down, whereby the dew point is lowered and water

can condense. However, this condensing water is brought by the drying stage 12 to the outside 42 of the device and so removed. If water droplets have formed on cooling or have already been present in the respiratory gas flow, they will be released during cooling

Continued flow of the respiratory gas stream A is received by the liquid storage 13. As a result, however, the gas temperature can continue to decrease and it can lead to a condensation of moisture by falling below the dew point. However, as it flows through the following hose section 11 ', which is also designed as a drying step 14, it also flows to the

Outside 42 of the device 10 transported. In addition, the condensation with the help of

Drying stage 14 are avoided by the dew point of the gas is lowered by means of the drying stage 14 below the ambient temperature. The respiratory gas flow A is in this way at

Reaching the end 17 that no more disturbing moisture is present when entering the gas analysis system G.

Also in the embodiments illustrated in FIGS. 2 and 3, the device 10 has a first and a second hose section 11, 11 'and a diameter D, which is dimensioned as already described above for FIG. It can also be seen here that the device 10 has a first end 16, through which a respiratory gas flow A coming from a respiratory system B enters the

Device flows in, and a second end 17, through which the breathing gas flow A flows out of the device 10 and out to a gas analysis system G out. Also, the device 10 shown in Figures 2 and 3 has a liquid storage 21. This liquid storage 21 is formed wick-shaped. It forms a drying element 20 together with a drying stage 22.

The wick, i. Thus, the liquid reservoir 21, thereby has the shape of a circular disk with a hole 214 in the center, a circular area 213, an inner edge 211 and an outer edge 212. The area of the circular surface 213 and the outer edge 212 are disposed within the drying element 22. The inner edge 211 is disposed between the first tube section 11 and the second tube section 11 '. In this respect, the liquid reservoir 21 is at least partially disposed between two tube sections 11, 11 '. Thus, it can be seen that in the exemplary embodiment of FIG. 2 -as well as in the example shown in FIG. 3-at least one liquid reservoir 21 is arranged in one of the drying stages 22, so that it has a Part of a drying element 20 forms. The respiratory gas flow A flowing through the device 10 first flows through the first hose section 11, then through the first hose section 11

Liquid storage 21, namely through the hole 214 in the liquid storage 21, and finally through the second tube section 11 '. It can be seen that the liquid storage 13, 21 in all in the Figures 1, 2 and 3 shown embodiments between the first and a second tube section 11, 11 'is arranged, so that the respiratory gas flow A, the device 10 in the

sequence

a. first tube section 11

b. Liquid storage 13, 21 c. second tube section 11 'passes.

The wick-shaped liquid reservoir shown in FIGS. 2 and 3 may also have a different shape in an alternative embodiment (not shown), for example with a polygonal outer contour or the like, it being essential that it has a section extending between the first and the second tube portion 11, 11 'is arranged so that its main surface is disposed within the drying stage 22.

The drying element 20 formed from liquid reservoir 21 and drying step 22 is arranged on the outside 42 of the device 10. In this case, the outer side 44 'of the drying stage 22 forms part of the outer side 42 of the device 10. The inflowing with the breathing gas stream A

Moisture is conducted from the liquid reservoir 21 to the inside 43 'of the drying step 22 and passes from the inside 43' of the drying step 22 to the outside 42 of the device, which corresponds to the outside 44 'of the drying step 22 in the region of the drying element 20.

As already described for FIG. 1, the respiratory gas flow A entering device 10 in FIG. 2 also typically has a temperature of 37 ° C. at first end 16. While the respiratory gas flow moves through the first tube section 11, the temperature here also drops and it condenses water. This is taken up by the liquid storage 21 and passed by means of capillary forces to the drying stage 22, to be removed from there from the device 10 by the

Liquid from the inside 43 'of the drying stage 22 is brought to the outside 42 of the device 10. After flowing through the liquid reservoir 21 of the cooled and

dried breathing gas flow A further through the second tube section 11 'moves. Ideally, the drying element 20 is arranged on the device 10 in such a way that the respiratory gas flow A has already cooled to such an extent on reaching the liquid reservoir 21 that in the second

Hose section 11 'condensed out no more water from the breathing gas flow A, or that the dew point of the breathing gas flow A is already lowered so far that no further water

can condense.

In the exemplary embodiment illustrated in FIG. 3, in addition to the drying element 20, the tube sections 11, 11 'are designed as drying steps 12, 14, as already explained with reference to FIG. 1. These lead as described for Fig. 1 auskondensierendes water and / or gaseous water vapor from the breathing gas stream A before and after flowing through the liquid reservoir 21 to the outside to the outside 42 of the device 10 from. In this respect, it can be seen that, in the exemplary embodiments shown in FIGS. 1 and 3, at least one tube section 11 is used as a Drying stage 12, 14 is formed. In particular, the device 10 has these

Embodiments a first and at least one second drying stage 12, 14, wherein the liquid storage 13, 21 is arranged between the first and the second drying stage 12, 14, that the respiratory gas flow A, the device 10 in order

d. first drying stage 12

e. Liquid storage 13, 21

f. passes through second drying stage 14.

Both in the tubular liquid reservoir 13 shown in FIG. 1 and in the liquid reservoir 21 of FIGS. 2 and 3 integrated in the drying element 20, the liquid reservoir 13, 21 is each selected from a hydrophilic porous plastic sintered element, a nonwoven, a plasma-treated PE granules (polyethylene granules) or a matrix of microstructured plastic particles.

In yet another embodiment, it is conceivable that the device 10 has a first tube section 11 and a plurality of further tube sections 11 '. In this case, the first tube section 11 may be a simple plastic tube section, a directly on it

adjacent second tube section 11 'may be formed as a drying stage 12. This can be followed downstream by a further tube section 11 ", which is designed as a liquid store 13 or again as a simple plastic tube, and one or more drying elements corresponding to the drying element 20 shown in FIGS. 2 and 3 can also be arranged downstream or upstream can get more

Connect hose sections, which are optionally designed as a drying stage, liquid storage or simple plastic hose. It can be seen that even a drying stage 12

according to the present invention between two tube sections 11, 11 'may be arranged.

In all embodiments shown and not shown, optionally on the outer side 44, 44 'of one or more drying stage 12, 14, 22, a drying agent, preferably zeolite, silica gel or the like, be applied. In another, not shown alternative

Embodiment, it is also conceivable that the liquid reservoir 13, 21 and the bacteria filter 15 form a single component.

Both in the embodiment shown in Figure 1 and in the illustrated in Figures 2 and 3 and the embodiments not shown, the breathing gas stream A when entering the device 10 through the end 16 typically has a temperature of about 37 ° C. This corresponds to the body temperature of a patient who has breathed out the respiratory gas flow A. By the transport through the device 10 toward the second end 17 of the respiratory gas stream cools A and water can condense out of the breathing gas stream A. In this case, the dew point of the respiratory gas flow A is optionally by the first

Drying stage 12 or 22 reduced so that it is at or below room temperature, for example at about 25 ° C, about 20 ° C or even about 15 ° C. In this case, droplets can condense, which are then taken up by the subsequent liquid storage 13 or by the hydrophobic bacterial filter 15 and stored or passed to the drying stage 22 and discharged to the outside. By the

Removal of the droplets from the respiratory gas flow A, the dew point rises again.

Test of different membrane materials

The drying stage 12, 14, 22 of the embodiments described above consists of a gas-tight, moisture-permeable material.

In Table 1, different such membrane materials are on interaction with

Anesthetics have been tested. In this case, a mixture of 2 vol .-% isoflurane in air in

Variation with pure air through hoses that have the corresponding membrane material sucked in, and the rise and decay time (T _up = rise time, T _dow n = decay time (each T10-90 times, T _rise = arithmetic mean) of a gas sensor detected anesthetic agent.

Polyurethane 15 17 1200/2200 433 496 465

Base

*: Permeation without / permeation with contact to liquid water

Materials having the properties listed in the table are available, for example, under the following trade names: Collano V 842-1, Epurex Platilon, API MZ 1001, Collano Tex, Arnitel VT308. Of course, the list of these materials is not exclusive, other materials having corresponding properties are of course also suitable for the practice of the present invention.

In all the illustrated embodiments, it is possible for the at least one drying stage 12, 14, 2 to comprise a membrane based on polyether-imides, polyether-blockamides or polyurethanes. In particularly preferred embodiments, the membrane consists of a material based on thermoplastic polyurethane. The membrane material has a density of 0.5 to 1.8 g / cm ³ , preferably 0.7 to 1.5 g / cm ³ , more preferably from 1 to 1.3 g / cm ³ , most preferably from 1, 2 ± 0.1 g / cm ³ , a melting range between 100 ° C and 200 ° C, preferably between 120 ° C and 180 ° C, more preferably between 140 ° C and 170 "C, most preferably from 150 ° C to 160 ° C, and a water vapor permeability of greater than 500 g / m ² per 24 hours, preferably greater than 1000 g / m ² per 24 hours, more preferably greater than 1500 g / m ² per 24 hours, most preferably greater than 2000 g / m ² per 24 hours For better processability, the membrane is applied to a polyethylene carrier (PE carrier).

LIST OF REFERENCE NUMBERS

A breathing gas flow

B ventilation system

D diameter

G gas analysis system

10 device 212 edge

11, 11 'hose section 213 surface

12 drying step 214 hole

13 liquid storage 22 drying stage

14 drying stage

15 bacteria filter 41 inside

16 end 42 outside

17 end 43 inside

44 outside

20 drying element 43 'inside

21 liquid storage 44 'outside 211 edge

Claims

claims

1. Device (10) for removing a respiratory gas flow (A) from a respiratory system (B) and for transporting the respiratory gas flow (A) to a gas analysis system (G), wherein the device (10) schlauchför mig with an inner side (41) and a Outer side (42) is formed and at least two tube sections (11, 11 ') and

• at least one drying stage (12, 14, 22) having an inner side (43, 43 ') and an outer side (44, 44'), and

Having at least one liquid reservoir (13, 21),

wherein the drying stage (12, 14, 22) at least partially consists of a gas-tight and moisture-permeable material such that moisture from the inside (43, 43 ') of the drying stage (12, 14, 22) by the gas-tight and

moisture - permeable material to the outside (42) of the

tubular device (10) is transportable,

and wherein at least one drying stage (12, 14, 22) and / or a liquid store (13, 21) is arranged at least partially between two tube sections (11, 11 ').

2. Device according to claim 1, characterized in that the liquid storage (13, 21) is selected from a hydrophilic porous plastic sintered element, a nonwoven fabric, a plasma-treated PE granules or a matrix of microstructured

Plastic particles.

3. Apparatus according to claim 1 or 2, characterized in that the liquid reservoir (13, 21) between a first and a second tube section (11, 11 ') is arranged, so that the respiratory gas flow, the device in the order

a. first hose section (11)

b. Liquid storage (13, 21)

c. second tube section (11 ') passes through.

4. Device according to one of the preceding claims, characterized in that at least one tube section (11, 11 ') as a drying stage (12, 14, 22) is formed.

5. Device according to one of the preceding claims, characterized in that the device (10) has a first and at least one second drying stage (12, 14), wherein the liquid storage (13, 21) in such a way between the first and the second

Drying stage (12, 14) is arranged, that the respiratory gas flow (A), the device (10) in the order

a. first drying stage (12)

b. Liquid storage (13, 21)

c. passes through the second drying stage (14).

6. Device according to one of the preceding claims, characterized in that at least one liquid reservoir (13) is tubular.

7. Device according to one of the preceding claims, characterized in that on the outer side (44, 44 ') of at least one drying stage (12, 14, 22) a

Desiccant, preferably zeolite, silica gel or the like, is applied.

8. Device according to one of the preceding claims, characterized in that at least one liquid reservoir (21) in one of the drying stages (22) is arranged so that it forms part of a drying element (20).

9. Device according to at least one of the preceding claims, characterized

characterized in that at least one liquid reservoir (21) is wick-shaped.

10. Device according to one of the preceding claims, characterized in that the at least one drying step (12, 14, 22) comprises a membrane based on polyether imides, polyether block amides or polyurethanes.

11. The device according to claim 10, characterized in that the material of which the membrane is made, a material based on polyurethane, wherein the

membrane material

b. a melting range between 100 ° C and 200 ° C, preferably between 120 ° C and 180 ° C, more preferably between 140 ° C and 170 ° C, most preferably from 150 ° C to 160 ° C, and / or

c. a water vapor permeability of greater than 500 g / m ² per 24 hours, preferably greater than 1000 g / m ² per 24 hours, more preferably greater than 1500 g / m ² per 24 hours, most preferably greater than 2000 g / m ² per 24 hours ,

12. The device according to claim 10 or 11, characterized in that the membrane is applied to a polyethylene carrier.

13. Device according to one of the preceding claims, characterized in that the device comprises a hydrophobic bacterial filter (15), wherein the bacterial filter (15) is preferably a PTFE membrane having a pore size of 0.45 μηι or less and a water intrusion pressure of 100 kPa or higher.

14. Device according to one of the preceding claims, characterized in that the liquid storage (13, 21) and the bacterial filter (15) form a single component.

15. A system for breathing gas monitoring of a patient, comprising the device (10)

according to one of claims 1 to 14.